text: The glycogenin-1 gene, which spans over 13kb, consists of seven exons and six introns. Its proximal promoter contains a TATA box, a cyclic AMP responsive element, and two putative Sp1 binding sites in a CpG island, a DNA region with a high frequency of CpG sites. There are also nine E-boxes that bind the basic helix-loop-helix of muscle-specific transcription factors.